Master Cylinder Questions

Just picked up a 2012 Prius after owning several 2nd gen Priuses. It wasn’t until I was driving home that I realized what that cycling hum was. Duh

it is currently cycling every 5-10 seconds so I assume it’s overdue

is there any option to exercise the master cylinder using tech stream? My gen2 had an ABS light on when I bought it and I was able to turn that off after going through some diagnostic process that had all the valves firing. I would probably flush the fluid first

When it comes time to replace parts is there a way to know which part needs replacement. I assume the pump outlives the Master cylinder

is tech stream used after install? Hopefully the version I have used on the gen2 works here as well

thanks all!

 

I am going to start answering my question. Please feel free to respond.

Looks like the techstream is not as much the issue here as the miniVCI cable. I am lucky that I don't need immediate use of my Prius, so I will probably see if I can go through the brake bleed and recalibrate procedure, if nothing else, to test that my setup works before ordering any parts. If it doesn't work, I can buy and return amazon cables that don't work and keep the one that does. BTW, if replacing brake fluid and bleeding stops the pump from cycling, I will wait to do anything else.

I also believe that the master cylinder (connected to pedal) is the culprit and not the unit with the pumps/storage. sorry I don't have the jargon here. I will pickup a replacement from an online dealership and replace only the MC. (~$600). I can always go back in and replace the second component. These are expensive enough to make it worth the extra legwork.